Process for carbonizing materials



July 14, 1931.

w..v E. TREN-r PROCESS FOR CARBONIZING MATERIALS Filed May 18, 1925 2Sheets-Sheet l .Ono

lll/11111111111 W. E. TRENT July l14, 1931.

POCESS FOR CARBONIZING MATERIALS Filed May 1 8, 1925 2 Sheets-Sheet 2yllIlIlIllIlIlI/Il ....II 0D.. 4 louf l IRO lin-.10b

Patented July 1,4, 1931 UNITEIS STATES WALTER EDWIN TRENT,`F NEW YORK,N. Y., ASSIGNOR T0 TRENT PROCESS CORPORA-4 TION, 0F NEW YORK,- N. Y., A

CORPORATION OF DELAWARE y PROCESS FOR OARBONIZING ATERIALS Applicationled May 18,

This invention relates to a process for carbonizing or otherwisetreating materials having avolatile content, such for instance, ascoals, lignites, or mixtures o'f oil and coal.

In the treatment of coals itis recognized that different productswillvaporize from the coal at progressively increasing temperatures. Theprimary products of distillation usually will be removed when the coalis subjected to a temperature of sayI4 500 centigr'ade. The secondaryproducts leave the `cda] when its temperature is raised from 500 to 1200centigrade, it being fully recognized that dierent reactions occur atdifferent temperatures.

The present invention relates rprimarily to a process in which` a bodyof coal or like material is continuously moved through a retort andduring its passage through said retort passes through successiveindependent heat- .ing zones maintained atl difereiit temperatureswhereby the volatiles removed Vfrom u the coal by reason of saiddifferent temperatures may be separately collected, if desired. In thevprocess I find it desirable at times`to pass gases and: vapors takenfrom one zone, or certain fractions thereof to a succeeding zone whichmay1 be maintained at a higher or lower temperature than the zone wherethese products were produced.

A further object ofthe invention is rtolprovide a process in which thematerial traveling through the retort is subjected to the direct actionof heating gases when passing through the different independent zones inthe retort. Iin this process the heated gases e are compelled to passthrough the fuel bed before they are permitted to escape and the vaporsan gases discharging from each compartment may be separately collected,or they may-be further treated by returning them to either a hotter orcooler compartment or zone in the retort. As a last step of treatment,it is generallypreferable to return the hottest vapors andgases back tothe first compartment for the purpose of utilizing their excess heat4 inthe green fuel, and to also reduce the work placed on the condensers.The invention in a modified form also comprises a process wherein coalor like materlal is passed 1925. serial No. 31,2?1.

the heating gases directed on the material at this time will continue toadd heat thereto as theyl travel along the bed of material to a pointWhere the fuel still remains green and is porous, or they will travelwith the fused material toward the discharge end of the retort at whichpoint the fused material becomes hard and porous to permit thepenetration of the gases.y f

In the 4accompanying drawings, I have merely shown-the preferableembodiment of my invention. Theapparatus herein shown is'disclosed forthe purpose of illustrating a highlyfsuccessful mechanism forv carryingout vmyprocess. r

In the drawings, Fig. 1 represents a longitudinal sectional view throughthe apparatus.

Fig. 2 is a modified form with two of the treating zones shown in Fig. leliminated,

Referring now more particularly to Fig. 1, the numeral 1 designates anelon ated retort having disposed therein an en less conveyor 2consisting of pivotally connected perforated pans 3, the conveyortraveling around the sprockets 4 and 5. lEither one of these sprocketsmay be operated by power means to impart to the conveyor a continuousmovement through the retort. At one end of the conveyor there isprovided `a hopper. 6 by means of which raw material such as pulverizedcoal or mixtures of coal and oil are fed to the conveyor.

'he retort intermediate'its ends is provided with a series of partitionwalls 7, 8, 9 and 10 which divide the r'etort into compartments A, B, C,D, and E. Underlying each compartment I also provide independent vaeuvinn

' volatiles contained in the coal distil off at tion, the gases'andvapors of primary distillation are formed at a temperature of say 500centigrate. At a temperature of from 500 to 7 00 centigrade fixed gasesand .tars appear, and within this range of temperature the products ifpassed through the fuel bed, will be largely converted to motor fuelstock. At 600 centigrade or higher, when steam is brought into contactwith the heated fuel, it is decomposed, liberating hydrogen, and theloxygen forms carbon monoxide gas with the carbon.- Then part of thehydrogen combines with the nitrogen that is released by thedecomposition of the coal and forms ammonia. If the gases carrying theammonia vapors are at once conducted to lower temperatures, the ammoniadoes not suffer seyere decomposition. It therefore follows, that inaccordance with this invention I mailitain the various zones of theretort at different and-preferably at progressively increasingtemperatures so that the dierent prod-v ucts derived 'from the coal atvarious temperatures may be so collected and treated as to not beseverely decomposed when such a decomposition is not preferable, andwhich objection would otherwise be present if the coal were permitted topass through a continuous retort where all the gases are 'permitted tocommingle.

In the apparatus shown in Fig. 1, the coal when passing through zone A,is heated to a temperature of say 500 centigrade. This occurs by reasonof heating gases Generated by the burners X, a row of parallel burnersbein arranged` in this zone A. These burners irect their gases`downwardly on the bed of fuel passing through this retort on theconveyor, vaporizing certain products therein which pass downwardly intothe pan l1. The Zone B is heated to a higher temperature than the zoneA. This zone may be heated to a temperature of 600 centigrade by nieansof the burners X which are of the same construction as the burnersdescribed in the zone A. Similar' burners are used in the zones C'and D,and in accordance with this invention the zoneC may be heated to say 700centigrade and the zone D'to 800 centigrade. These temperatures are onlygiven for the purpose of illustration and can of course vary dependingupon the materials il: being treated and the products desired. In

composes when brought into the presence of' heated carbon at atemperature in excess of 600 centigrade. In the compartmentE Ipreferably provide a water or steam discharging jet 20 by means of whichsteam or water is introduced to this compartment for the purpose ofcontacting with thebed of 4heated or carbonized fuel which is at thistime at a very high temperature. This contacty causes a decomposition ofthe steam forming the gases to which I have heretofore alluded. Theformation of this gas is well known to those skilled in the art and neednot be repeated in this specification. As the fuel passes from the zoneE, it becomes porous and broken and discharges into the hoplper 17 inthe form of a solid carbonized lle The productsof decomposition producedin the zone B may be withdrawn from this zone through the line 21 to acondenser, collector or the like, or in fact any plant suitable for therecovery of these products. The same also applies in connection with thezones C, D and E, as each zone has a drawoff line 22, 23 and 24respectively for this pur ose. The Zone A furthermore has a drawo line25 which may lead to a producer gas recovery plant, and a seconddrawofll line 26 which may also lead to a condenser or the like, itbeing understood that all of these drawof lines are provided withsuitable valves. It Will be seen however, that a second drawoff line 26afrom the pan 12 of the zone B leads by means of the line 27 to the upperend of the compartment D, into which 'it discharges through tube 19f.Gases carrying ammonia are transferred through this line to thiscompartment.

The pan 13 of the compartment C is also provided with va second drawoffline 28 leading through line 29 to the compartment or zone A, into whichit discharges through tube 19 so that the intensely hot gases applytheir heat to the green material passing through this zone. Obviouslythis utilizes the excess heat ofthe gases and reduces the labor placedon the condenser. In the illustration disclosed in Fig. 1, I have notshown the drawoff line 30 leading from the pan 14 of the compartment ascommunicating with any of the other compartments or zones of the retort.However, this line can communicate with any one of these zones dependingupon the work that is` to be done, or it may, if desired, as shown, leadto any other apparatus such as a water gas recovery plant vforrecovering gas, ammonia, etc. The line 31 communicating With the pan 15of the l,

compartment E, which isI the compartment in Which'steam is introducedfor the production of wvater gas, practically leads by means of the line32 directly to the compartment or yzone B, into which it dischargesthrough tube 19h. Steam and blue gas for collecting ammonia are usuallypassed through this .line as such products are generally produced in thecompartment E. It has been explained that from this compartment B thegases pass to the compartment D, and from this compartment they arewithdrawn without any further introduction to other compartments orzones of the retort for the recovery of gas, ammonia, etc. It willfurthermore be understood that this arrangement of the gasconveyingpipes may be materially altered, and that the present specificationmerely describes a process which has been found to be highly desirablein the production of certain desired products. If other products aredesired, the gases from one retort may be shifted to another as theaction may demand.

In Fig. 2 of the drawings I have shown a slightly modified form of theinvention wherein I have eliminated a water gas producing zone shown asE, in Fig. 1. In this figure, however, I have merely shown the apparatusas having three condensate collecting pans. The parts of the apparatusshown in this figure are all the same, and a detailed description neednot be given. It suiiices to say that in this embodiment of theinvention vapors and gases from the zone -B pass through the line 33 tothe zone A', while vapors and gases from the zone A, may in thisembodiment of the invention pass through the line 34 to the zone C. Thisprocess isused when it is desired to conveyhot gases from the zone B tothe zone A to recover their heat, and when such 'gases and vaporsfromzone A need superheating in zone C, to be cracked .for the recoverynoflight oils, gases, etc., the

products are discharged through the line 35 from this zone.

2 In the modified form of the invention shown in Fig. 3, I have provideda retort adaptedprimarily for the low temperature carbonization of coal.That is to say, in this retort I do not have in mind the utilization ofthe high temperatures practiced in the invention carried out in theapparatus shown in Figs. 1 and 2, and in which apparatus I have 'foundit essential to divide the retort infto compartments` because of thetemperatures employed. InrFig. 3 theV retort 40 is of an elongatednature .having a belt or, endless conveyor 41 consisting of a serles ofpivotally connected perforatedA pans, which conmaterial to the conveyorin a thin bed and move the conveyor rapidly through the re.- tort. Thebed of material in this operation is considerably .thinner than the bed.applied to the conveyorsin Figs. 1 and 2 of the ap# paratus. In theoperation of this process it Will be observed that in thezone designatedby the line m-m the material becomes fused and more or. lessimpervious'to the heating gases. 'Ehese gases however, will travel alongth Vconveyor to the left and penetrate the greerpcoal before it reachesthe zone w-m and before fusion takes place, and Will travel to the righttowards the discharge end of the conveyor and will penetrate thecoke-like mass after it has become hard and porous. In other words, whenthe mass isJpassed through the zone" :1vit is often in that state offusion where gases cannot penetrate, but as soon as it becomes hard andleaves this zone it becomes more or less porous, permitting penetrationof the heated gases generated, which have been described.

I claim 1s f. 1. A process of the character described,

comprising passing a body of solid carbonizable fuel successivelythrough zones of progressively increasing temperatures, undercarbonizing conditions, removing volatiles from one zone and passingsaid volatiles to a succeeding zone of a higher temperature suiicient tocrack the hydrocarbon vapors contained in said volatiles into light oilvapors but insuficient to completely decompose said volatiles.

2. A process of the character described, comprismg passing a body ofsolid carbonf izable fuel successively through zones of progressivelyincreasing temperatures, under carbonizing conditions, removingvolatiles from one zone and passing said volatiles to a succeeding zoneof a higher temperature Sullicient to crack the hydrocarbon vaporscontained in said volatiles into light oil vapors but insuiicienttocompletely decompose said volatiles, and thereafter introducing steam tothe material passing through one of the higher heated zones to .bedecomposed tand' converted into gas.' y

3. process of the character described comprlsing passing a body of solidcarbonizable fuel successively lthrough zones of progressivelyincreasing temperatures under carbonizing conditions, removing volatilesfrom one zone and passing same to a succeeding-Zone of a highertemperature suf' .cient to crack the hydrocarbon vapors contained insaid volatiles into light oil vapors but insufficient to completelydecompose said volatiles, thereafter introducing steam to the materialpassing through one of the higher heated zones to be decomposed andconverted into gas, and introducing the gas from said zone to one of thecooler zones to impart its heat to the green fuel therein land enrichsaid gas.

4. A process for obtaining volatiles from solid carbonaceous materialWhich yields volatiles upon destructive distillation which comprisescontinuously moving said material through a plurality of successiveheating zones, destructively distilling the material by introducing anindependent stream of hot gas to the material in each of said zones,said gas being in sufficient amount and of sulicient temperature todestructively distil said material, removing resultant volatiles fromeach of said zones, and introducing volatiles removed from one of saidzones into Contact with the material in a succeeding one of saild zones.i

In testimony whereof I aflx my signature.

WALTER EDWIN TRENT.

